Astronomers have discovered three ancient stars that once belonged to the first galaxies of the universe, now ‘hiding’ at the edge of the Milky Way, according to a report published in the Monthly Notices of the Royal Astronomical Society.
The Milky Way is believed to have absorbed other galaxies during its growth. (Image: AI).
Researchers from the Massachusetts Institute of Technology (MIT) have identified three elderly stars located about 30,000 light-years from Earth, in an area known as the halo of the Milky Way.
The basic chemical composition of this group of stars indicates that they are between 12 and 13 billion years old, meaning they originated from some of the first galaxies formed after the Big Bang, which occurred 1 to 2 billion years later.
“The trio of stars is moving quite fast, reaching speeds of hundreds of kilometers per second (and in the opposite direction of other stars)”, according to the MIT report, further suggesting that these stars do not belong to the Milky Way but rather originated from other galaxies.
Researchers believe that the number of ancient stars present in the Milky Way is not limited to just three; it could be many more. They are considered “fossil” evidence that exposes the past, indicating that the Milky Way has grown by absorbing surrounding galaxies and stealing their stars.
These ancient stars may also be used to study the first stars and galaxies of the universe.
“The group of ancient stars is part of our cosmic family tree. And now we know where to look for them to study,” said research team member, Professor Anna Frebel.
